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Subwoofer wire: coax r59... mega LOUD feedback

I have an Onkyo 780 and some guy at Home Depot said I could use the existing r59 coaxial cable that was under my house to hook up the subwoofer. I put on the jacks and it did work, so I was pretty happy, until my wife said that the subwoofer started giving really loud feedback. She had to unplug the subwoofer.

I was wondering if the coax cable is the problem? It is plugged into the wall, away from the TV, and about 1 foot next to the left speaker. I have the front speakers set to "large," and the subwoofer turned all the way up (otherwise it didn't turn from standby to on).


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In reply to: Subwoofer wire: coax r59... mega LOUD feedback

oN THE BACK OF THE AMP THERE WILL BE AN R.C.A. JACK LABELED SUB OUT. Use this only then run an r.c.a. cable to your sub You may have 2 inputs on your sub labeled sub in L+R then just get a r.c.a. y conector . then turn your volume control all the way off and bring up the level that sounds rite to you you shouyld never go more than a third way up on the level in closing run a test tone on your amp and set the sub to 0 d.b. good luck

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existing r59 coaxial

In reply to: Subwoofer wire: coax r59... mega LOUD feedback

Existing??? What was it used for??? John

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In reply to: existing r59 coaxial


The coax was probably used to route cable TV from one room to another, but my question is what kind of connector could be put on a coax cable that would connect to a subwoofer and the other end to the amp? I've never seen a subwoofer with an F-Connector fitting. Weird, no?

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In reply to: Coax

There are plenty of adapters out there, f to RCA is a common one.
A bad connection can make a subwoofer "hum" and it is possible for it to be loud. If you remove the end from the receiver, and leave the sub ON, all you have to do is touch the RCA end and the sub could hum. Coaxial cables often get used for this purpose, but it really isn't the right way to do it.

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I think this is it

In reply to: Adapters

The coax was to route the cable to another room indeed, and thought I could save time/money by using it for the subwoofer.

It does work, but my wife said that it all of sudden went ballistic. I did have it turned up the max, but have now turned it down half-way. Will see if this works, and if not, will buy a longer RCA cable to replace the coax.

Better that than to scare the bejesus out of the cats.


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